The present invention relates to computers, and more particularly to data storage devices that include one or more automated loading subsystems that are designed to load/unload storage media into/from one or more data storage drives.
Providing users with large capacity data storage devices at a reasonably low cost has long been the goal of both disk drive and tape drive manufacturers. With the introduction of faster processors/data links, cheaper memory and more powerful software applications, there is an even greater need for large capacity data storage devices.
Magnetic disk drives tend to provide a relatively large capacity data storage capability. Conventional magnetic disk drives, however, are not well suited for longer-term data back up. For more secure, longer-term data back up, magnetic tape drives, removable magnetic disk drives, and/or optical disc drives tend to be better choices. With these data storage drives, a storage media, such as, for example, a tape cartridge, a magnetic disk, or optical disc, can be selectively accessed and later removed and perhaps stored in a safe location until and/or if needed.
Those users with the need to provide even more data storage capability, or perhaps ready access to data stored on storage media, can utilize one or more automated media loading devices (i.e., an automation controller) designed to automatically load/unload storage media into/from one or more data storage drives.
By way of example, FIG. 1 is a block diagram depicting a conventional data storage system 20 having a host computer 22, a storage drive 24 and an automation controller 26. Host computer 22 is configured to send/receive data to/from data storage drive 24, and to send/receive other commands to/from data storage drive 24 and/or automation controller 26. Data storage drive 24 can be a magnetic tape drive, a magnetic disk drive, an optical disc drive, or the like. Data storage drive 24 is configured to selectively access at least one storage medium during a read or write operation.
Automation controller 26 is operatively configured to selectively position a storage media, as required for access by data storage drive 24, in support of the read or write operation. To accomplish this, automation controller 26 typically includes mechanical mechanisms, such as, for example, robotics, that are configured to move the correct storage media into a proper position for reading from or writing to by data storage drive 24.
As can be appreciated, there is an inherent need to carefully control the operation of data storage drive 24 and automation controller 26 during a read or write operation. Typically, automation controller 26 is controlled by commands provided from host computer 22, and data storage drive 24 is controlled by commands from both host computer 22 and automation controller 26. In such a configuration, automation controller 26 is essentially a xe2x80x9cmasterxe2x80x9d device and data storage drive 24 is essentially a xe2x80x9cslavexe2x80x9d device.
Commands from host computer 22 to automation controller 26 and data to/from data storage drive 24 are carried by link 27. Link 27 is usually a small computer system interface (SCSI) link that also carries data during the read or write operation.
Commands from automation controller 26 to data storage drive 24 are typically carried over a standard serial interface 30, such as, for example, an RS-422, or other like serial interface. Serial interface 30 typically allows automation controller 26 to co-coordinate activities with data storage drive 24, for example, by obtaining information (e.g., status, etc.) from data storage driver 24. This unidirectional information flow is one result of the master/slave relationship.
The configuration in FIG. 1, however, requires that both data storage drive 24 and automation controller 26 have SCSI interfaces. This requirement tends to increase the cost to the user. In more recent configurations, link 27 includes a Fibre Channel link. This requires that both data storage drive 24 and automation controller 26 have Fibre Channel interfaces, or that a bridge 28 or like device be introduced to bridge between Fibre Channel and SCSI interfaces in data storage drive 24 and automation controller 26. Both of these solutions can be very expensive to the user. Alternatively, replacing existing data storage systems with newer models can also be extraordinarily expensive and time consuming.
Thus, there is a need to provide for lower cost methods and arrangements that allow users to continue to utilize existing data storage devices, while taking advantage of higher bandwidth links, such as, for example, Fibre Channel. Preferably, the improved methods and arrangements will extend existing interfaces without compromising backwards compatibility. Moreover, providing bi-directional control and bi-directional information flow would tend to improve the operation of the data storage device by providing for increased coordination and communication.
The present invention provides improved methods and arrangements that allow users to continue to utilize existing data storage devices, while taking advantage of higher bandwidth links, such as, for example, Fibre Channel. The various improved methods and arrangements extend existing interfaces without compromising backwards compatibility, and allow for bidirectional control and/or bidirectional information flow.
Thus, for example, the above stated needs and others are met by a data storage device, in accordance with certain aspects of the present invention. The data storage device includes at least one data storage drive, an automation controller, and an enhanced interface.
The data storage drive can be operatively coupled to a computer or like device and arranged to perform a plurality of operations in response to one or more commands received from the computer. The automation controller is configured to physically provide the data storage drive with at least one data storage media. The enhanced interface operatively couples the data storage drive with the automation controller, such that the data storage drive can be selectively controlled by the automation controller and the automation controller can be selectively controlled by the data storage drive depending on the received commands. This arrangement also allows for bi-directional information flow.
In certain implementations, for example, the enhanced interface includes a serial interface and at least one additional line. Here, the additional line is configured to provide a directing signal from the data storage device to the automation controller. In other implementations, the serial interface is further configured to provide a directing signal from the data storage device to the automation controller. As a result of the enhanced interface, the data storage drive and automation controller are capable of being connected to the computer through a single host interface within the data storage drive. For example, the host interface can include a small computer system interface (SCSI) or a Fibre Channel interface to the computer. The data storage drive can include a magnetic tape drive, a magnetic disk, an optical disc drive, or the like.
In accordance with certain further aspects of the present invention, an enhanced interface is provided for use in a data storage device having at least one data storage drive configurable and an automation controller. The enhanced interface includes a first automation controller interface (ACI) portion configurable within a data storage drive, a second automation controller interface (ACI) portion configurable within an automation controller, and a serial interface connected between the first ACI and the second ACI. The serial interface is configurable to provide a directing signal from the data storage device to the automation controller such that the data storage drive can be selectively controlled by the automation controller and the automation controller can be selectively controlled by the data storage drive depending on commands received by the data storage drive from a computer. This arrangement provides bi-directional flow of information.
In accordance with still further aspects of the present invention, a method for use in a data storage device having at least one data storage drive and an automation controller is provided. The method includes the steps of receiving a command from a host computer operatively coupled to a host interface within the data storage drive, and determining if the command is for the automation controller. If the command is for the automation controller, then the method includes the step of causing the data storage drive to send a directing signal to the automation controller over an enhanced interface that operatively couples the data storage drive with the automation controller. The method also includes the step of causing the automation controller to respond to the data storage driver upon receipt of the directing signal, such that the automation controller is selectively controlled by the data storage drive depending on the received command.